title: Ornithine decarboxylase from Saccharomyces cerevisiae. Purification, properties, and regulation of activity.
abstract: Ornithine decarboxylase has been purified 1,500-fold to homogeneity from a spe2 mutant of Saccharomyces cerevisiae which lacks S-adenosylmethionine decarboxylase and is derepressed for ornithine decarboxylase. The ornithine decarboxylase is a single polypeptide (Mr = 68,000) and requires a thiol and pyridoxal phosphate for activity. Addition of 10(-4) M spermidine and 10(-4) M spermine to the growth medium reduces the activity of the enzyme by 90% in 4 h. However, immunoprecipitation studies showed that the extracts of polyamine-treated cells contain as much enzyme protein as normal cell extracts. This loss of ornithine decarboxylase activity is probably due to a post-translational modification of enzyme protein because we found no evidence for any inhibitor of activity in the polyamine-treated cells.
mesh_terms: D000936:Antigen-Antibody Complex; D002262:Carboxy-Lyases / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D006207:Half-Life; D007106:Immune Sera; D005779:Immunodiffusion; D007700:Kinetics; D008970:Molecular Weight; D009955:Ornithine Decarboxylase / Q000302:isolation & purification / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013095:Spermidine / Q000494:pharmacology; D013096:Spermine / Q000494:pharmacology
chemical_list: D000936:Antigen-Antibody Complex; D007106:Immune Sera; D013096:Spermine; D003513:Cycloheximide; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D013095:Spermidine